Hydraulic pump or motor



W. ERNST HYDRAULIC PUMP 0R MOTOR May 23,1939.

Filed June 24, 1936 4 Sheets-Sheet l w wR INVENTOR man-e ERNST.

ATTORNEYS.

May 23, 1939. w. ERNST 2,159,553

HYDRAULIC PUMP OR MOTOR Filed June 24, 1936 I 4 Sheets-Sheet s 0 v F/.4. I I m9 I V m4 IN -NTOR WILTEE FENST ATTORNEYS May 23, 1939. w, ERNST mrmuuuc PUIP on uo ron 4 Sheets-Sheet 4 Filed June 24, 1936 F/f. m 92 6 mu m5 Patented I May 2 3, 1939 UNITED STATES PATENT OFFICE HYDRAULIC PUMP R MOTOR Walter Ernst, Mount Guess, om, asignor to The Hydraulic Press Corporation, Inc., Wilmington, Del., a corporation of Delaware Application June 24, 1936, Serial No. 87,028

2Claims.

connection, comprising a cross member mounted I on the piston and carrying anti-friction rollers engaging grooves in the secondary rotor, this construction beingadapted in operation to'cause the pistons to be reciprocated as the rollers travel back and forth in the grooves as the primary and secondary rotors oi' the pump rotate about their respective axes.

Another object isto. provide a hydraulic pump or motor of the type set forth in the preceding paragraph and having 'a piston and crosshead construction employing a transverse crosshead Y shaft passing through a bore in the upper portion of the crosshead and having axially spaced rows of needle bearings between it and the crosshead, the opposite ends of the shaft carrying rollers which engage corresponding grooves in thesecondary rotor of the pump, thereby eliminating the tendency for the needle bearings to cramp within the crosshead bore by reasonof the bending of the crosshead shaft during the operation of the pump or motor at high pressures; In the drawings:

Figure 1 is avertical longitudinal section through the hydraulic pump or motor of this invention.

Figure 2 is a vertical cross section through the 3 hydraulic pump or motor shownin Figure 1, takenalong the'lineI-I of Figure 1.

Figure 3/is an enlarged detail view of a modifled piston' and crosshead construction differing from.- that shown in Figure 1. I

Figure 4 is an enlarged detail view of the piston and crosshead construction and adjacent mechanism asshown in-Figure 1.

Figure 5 is an enlarged detail section of the modified construction shown in Figure 3, showing the modified.piston, wrist pin and crosshead rollers as applied to the structure shown in Fig- Figure 6 is a cross section taken on the line 6-4 of Figure '3, showing the modified anti-trio tion bearing construction of Figures 3, 5 and "I for the c rollers.

Figure 7 is a top plan view of the modified piston and crosshead construction shown in Figure 3, likewise showing the'adjacent ridges upon the primary rotor or cylinder barrel.

Figure 8 is a top plan view of the preferred form of piston and crosshead construction as shown in Figures 1, 2 and 4.

Figure 9 is a side elevation of the preferred construction shown in Figure 8.

Figure 10 is a detail view, partly in section, along the line io- -ili of Figure 9, showing the preferred piston and crosshead assembly of Figures 8 and 9.

In general, the pump or motor of this inven- 10 .tion consists of a primary rotor, a secondary rotor adapted to rotate upon an axis eccentric to that of the primary rotor, and pistons recip-- rocable in radial bores in the primary rotor, each piston having at its outer end a shaft mounted I in axially spaced rows of anti-friction needle bearings, the shaft having rollers on the ends thereof adapted to travel in tracks or grooves in the secondary rotor. As the primary and secondary rotors rotate about their respective g0 axes, the rollers on the ends of the pistons travel back and forth in theirtracks or grooves in the secondary rotor, and a reciprocation is imparted to the pistons. At the same time the rollers do not need to travel back and forth in the tracks as at thefull operating speed of the pump, but merely travel fast enough t'o'make up for the change in peripheral velocity as the primary and. secondary rotors turn on their respective antifriction bearings. Atthe same time the'piston executes a swinging movement about the antifriction bearings supporting its crosshead rollers. Referring to the drawings in detail, Figure 1 shows the hydraulic pump or motor of this invention as consisting of a casing i0 having end a plates Ii and I2 secured to the opposite sides thereof, as by the cap screws II.- The end plate ii is provided with an axial projection I, having a longitudinal bore it provided with transi verse bore i8 and I1 for the passage-oi pressure fiuid. 'Mounted in the longitudinal bore II is a 1 plntlela having a threaded portion I! which is engaged by a nut 20. The nuttil an incision 2i formed therein, the parts 22 and 23 of the nut 20, on opposite sides thereof, being engaged by the cap screw 24 loosely through the hole 25 in the part 22, and having its threads engaging the threaded hole It inthe part 23. .By this means thenut 20 may be adjusted 5 to the desiredpoint, whereupon thegtlghtening of the cap screw 24 causes the parts 22 and, 23 to be forced toward one another against the threads of the threaded portion i9, thereby causing the nut-2| to remain firmly lockedin posi- 55 charge passages.

direction.

The purpose of this nut 29 operating upon the threaded portion I9 is for axially or longitudinally adjusting the position of the pintle I8 in order to adjust the clearances of the antifriction bearings supporting the primary rotor of the pump, as will hereinafter appear. The nut 29 and threaded portions I9 are protected by a cover cap 21 secured to the end of the projecting portion I4 of the end plate II by means of the cap screws 28, threaded into the threaded bores 29 thereof.

The pintle I8 is provided with longitudinally disposed pairs of ducts 39 and 3I, respectively, one pair of these ducts serving as pressure fluid intake passages and the other pair as fluid dis- The passages 39 and 3| communicate, respectively, with the cut-away portions 32 and 33 in the reduced diameter portion 34 of the pintle; Mounted for rotation on the reduced diameter portion 34 of the pintle I8 is a races 49 are held in position by the retaining ring 44, secured by means of the set screws 45 to the threaded holes 46 of the primary rotor or cylinder barrel 35.- The outer race H is held in position by the forwardly projecting flange 41 of the enlargement 49 on the inner end of the drive shaft 49', secured thereto by the set screws 59 engaging the threaded holes in the primary rotor 35.

The inner bearing race 31.is engaged by an end plate 52, secured to the inner end of the pintle I8 by means of the cap screws 53 secured within the threaded holes 54, and witha washer or a plurality of shims 55-arranged therebetween. The inner race 36, however, is loosely mounted so as to slide upon the reduced diameter portion 34 of the pintle I9, and between it and the inwardly projecting flange 56 of the end plate II is arranged a sliding ring 51. As a consequence, it will be seen that the turning of the nut 29 upon the threaded portion I9 of the pintle I8 will cause the pintle to move axially. Assuming that this motion is to the left (Figurel) the end plate 52 will force the inner race31 to engage the rollers 39. These, 'in turn, engage the outer race 4| and force it and the primary rotor 35 tothe left, together with the opposite outer race 49 and its rollers 38. The inner race 36, however, is prevented from moving 'to the left'because o! the presence of the sliding ring 51 engaging the flange 56 on the end plate II, and consequently remains stationary while the pintle portion 34 slides through it. The result is that the diametrical clearances of the anti-friction bearings 33 and 39 are taken up in this manner so that the bearings may be kept at a tight fit without undue binding or looseness.

The primary rotor is provided with a bore 53 which engages the reduced diameter portion 34 of the pintle I9 with very narrow clearances.

The load, however, is taken by the tapered roller bearings 39, whose diametrical clearances may be adjusted to amounts less than the clearance between the primary-rotor bore 59 and the pintle portion 34. The latter clearance, therefore,.

diametrically opposed flattenedportions 1 artion, without the danger of slippage in either and yet to prevent excessive leakage therebetween.

The cylinder barrel 35'is provided with a plurality of radially disposed cylinder bores 59 having outlet ports 69 communicating at their inner ends with the cut-away portions 32 and 33 in the pintle I9. The cylinder barrel 35 is also provided with lubrication passages 6| for transmitting lubricant -therethrough. A similar lubricant passage 62 is provided in the drive shaft 49, the latter having an enlarged portion 63 adapted to support the inner races 64 of double tapered roller bearings 65, having an outer race 66 supported in an annular recess 61 in a projecting flange 68 in the end plate I2. The inner races 65 are held imposition by locknuts 69- and 19 having a washer 1I therebetween, these beingthreaded upon the threaded portion 12 of the drive shaft 49. The annular recess 61 is closed by an end' cap 13, secured thereto by'the set screws 14 mounted in the threaded holes 15 An oil retaining ring 16 surrounds the thereof. drive shaft 49' in order to prevent leakage along the drive shaft.

Mounted for reciprocation in. the cylinder bores 59 are pistons 99. In the preferred form of piston and crosshead construction shown in Figures 1, 2, 4 and 8 to 10, the primary rotor 35 is provided with a ridge I23 having recesses I24 imediately adjacent the tops of the cylinder bores 59. The piston 99 is provided with'a top having squared si es I25 and I26, the former being arranged to e gage the sides of the recesses .24 so as to be guided thereby. The piston head is provided with a transverse bore 92 adapted to receive the crosshead shaft. The latter is rotatably mounted therein bymeans of the double rows of needle bearings 95 (Figure 10) separated from one another by the annular ridge I21. Upon the ends 94 of the'pin 93 .are secured rollends I23. The flattened surfaces I26 on the piston crosshead (Figure '9) are provided with oil grooves. I29 (Figure 10) for conveying lubricant to the needle bearings 95.- p

The crossheadrollers 96 are arranged to engage grooves forming trackways 99 in the secondary rotorhalves I99. The latter are joined to-. gether by the set screws I9I', secured within the threaded holes I92 so that the halves I99 form, in effect, an integral secondary rotor. The latter is provided with annnular shoulders I93 adapted to support the inner races I94 ofanti-friction tapered rollerbearings I95, the outer races I96 being heldin position by the'retainingrrings I91 secured by the set screws l99 within the threaded holes I99 'of the shift ring Ill. The latter is provided' horizontally with diametrically opposed threaded holes. III, within which aremounted the threaded ends m of the shift rods I n, the whole being secured in position by the set screws I I4. Access to the set screws is obtained through the threaded plugs II5, closing the passages H6 in thecasing I9 of the pump (Figure 2 i I The shift ring H9 is provided vertically with ranged to engage the correspondingly flattened projections III! on the interiorwalls of'the pump casing I9. The shift rods II3 pass outwardly through the casing l9 by way of the bores II9.

ers 96, these being held in' place by the enlarged axis of the pintle I9 and cylinder barrel or primary rotor il when theshift ring us dar'y rotor halves ill. is supplied and removed is so placed the secondary rotor Ill revolves about an axis which is eccentric to that of the primary I -rotor It so'that the pistons II are caused to t reciprocate radially within their cylinder bores II by the engagement of their cros'shead rollers 08 with the grooves or trackways as in the secon- At thesam'e time fluid from the pump by the in pintle passages II and ti, communicating with the cylinder bores It by way of the ports 0 and cut-away portions 82 and 33. Ports ii. are provided atythe top and bottom of the shift ring I, thereby exposing the flattened projections 3- '8 to the action of the oil employed as fluid for the pump. d I

In the modified construction shown in Figures 3 and 5- to 7, the pistons II have flattened portions 8i upon their outer ends. Passing through. so the flattened portions ll, transverse of each piston, is a bore 92 within which ismounted a wrist pin as having redueed diameter portions It, on its op s te ends. The reduced diameter.por-

tions 94 are surrounded bybearings ll, prefersur- The wrist pin "is held" :5 ably needle bearings, rounded by rollers 08.

in position within the bore a: by a set screw-l1, threaded into the threaded hole the rotation of the pistons II in their cylinders I II, the pistons of the form of pump shown in Figures 3 and 5 to 7, inclusive.'are provided with keys lid secured in recesses III by means of set screws I32, and operating in corresponding grooves II! in the cylinder barrel SI.

theseinturn is, It will be understood that I'desire to comprehend within my invention such modifications as come within the mo invention.

Having thus fully described Patent, is:

' gaging said guide'way.

II. To prevent of the claims and the my inv n i 0 what! claim as new and desire'to secure byLet- 1. In combination in a hydraulic pump or motor, a primary rotor having cylinder bores, a secondary rotor encircling said primary rotor and having a guideway, pistons with transverse bores therein reciprocable in said cylinder bores, a plurality of spaced annular assemblies of needle bearings mounted in each bore, means for spacing the adjacent ends' of said needle bearings in said assemblies apart from each other axially, a piston crosshead shaft rotatably mounted in said needle bearings within each transverse piston bore, and rollers mounted on each cromhead shaft on opposite sides of each piston and enwhereby to eliminate the cramping action of said needle bearings in said assemblies arising from the bending of said crosshead shaft during the operation of said pump or motor.

2. In combination in a hydraulic pump or miotor, a primary rotor having cylinder bores, a

secondary rotor encircling said primary rotor and having a 'guidewa pistons with transverse bores therein reciprocable in said cylinder bores, a plurality of spaced annular assemblies of needle bearingsgmounted in each bore, a piston crosshead shaft rotatably mounted in said needle annular spacing member encircling said crosshead shaft for spacing the adjacent ends of said needle bearings in said assemblies apart from each other axially, and rollers mounted on each crosshead shaft on opposite sides of each piston and engaging said guideway, whereby to eliminate the cramping action of said needle bearings in said assemblies arising from the bending of said crosshead shaft during the operation of said pump or motor.

' wsLm'mas-r. 

